RNase non-sensitive and endocytosis independent siRNA delivery system: delivery of siRNA into tumor cells and high efficiency induction of apoptosis

• Published in: Nanoscale 2013-08, Vol.5 (16), p.7256-7264
• Main Authors: Jiang, Xinglu, Wang, Guobao, Liu, Ru, Wang, Yaling, Wang, Yongkui, Qiu, Xiaozhong, Gao, Xueyun
• Format: Article
• Language: English
• Subjects: Apoptosis; Cell-Penetrating Peptides - chemistry; Endocytosis; Gene Transfer Techniques; HeLa Cells; Humans; Hydrophobic and Hydrophilic Interactions; Microscopy, Confocal; Nanotubes, Carbon - chemistry; Ribonucleases - metabolism; RNA Interference; RNA, Small Interfering - metabolism; Static Electricity; TOR Serine-Threonine Kinases - antagonists & inhibitors; TOR Serine-Threonine Kinases - genetics; TOR Serine-Threonine Kinases - metabolism
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c3nr01183f

To date, RNase degradation and endosome/lysosome trapping are still serious problems for siRNA-based molecular therapy, although different kinds of delivery formulations have been tried. In this report, a cell penetrating peptide (CPP, including a positively charged segment, a linear segment, and a hydrophobic segment) and a single wall carbon nanotube (SWCNT) are applied together by a simple method to act as a siRNA delivery system. The siRNAs first form a complex with the positively charged segment of CPP via electrostatic forces, and the siRNACPP further coats the surface of the SWCNT via hydrophobic interactions. This siRNA delivery system is non-sensitive to RNase and can avoid endosome/lysosome trapping in vitro . When this siRNA delivery system is studied in Hela cells, siRNA uptake was observed in 98% Hela cells, and over 70% mRNA of mammalian target of rapamycin (mTOR) is knocked down, triggering cell apoptosis on a significant scale. Our siRNA delivery system is easy to handle and benign to cultured cells, providing a very efficient approach for the delivery of siRNA into the cell cytosol and cleaving the target mRNA therein. siRNA was successfully delivered into cytosol, escaping endosome/lysosome trapping and degradation by CPP and SWCNTs, and significantly cleaved mRNA.